Colloidal silica dispersions have previously been used inter alia as coating material to improve adhesive properties and increase wear and water resistance of various materials. However, these compositions, especially highly concentrated colloidal silica compositions, may be liable to gelling or precipitation, which considerably shortens the storage time.
EP 1554221 discloses a method of providing a dispersion of silane-modified silica. However, the stability of such dispersions may not always provide sufficient stability, hardness, and/or water resistance.
It would be desirable to provide an improved silanized silica sol dispersion with regard to the above deficiencies of the prior art. It would also be desirable to provide a highly concentrated colloidal silica dispersion for inter alia coating applications which can be easily stored and transported without any initial precipitation. A further object is to provide a dispersion imparting high water resistance and/or hardness, in particular early hardness, to lacquer formulations. It would also be desirable to provide a convenient and inexpensive method of producing such a dispersion.
A further object is to provide a dispersion suitable for wood lacquers which does not discolour the wood, for example oak. It is a further object of the invention to provide improved water resistance of wood lacquer formulations.